Jose Aldo has sustained a compacted vertebrae which could force him out of his first UFC featherweight title defence scheduled for Jan. 1 against Josh Grispi, according to reports.
Heavy.com first reported the injury, saying Aldo, the WEC title-holder who on Saturday was presented with his UFC belt, withdrew from the bout after sensing tingling in his arms. However, ESPN.com later cited the 145-pound champion's representative, who claimed Aldo "doesn't care about the injury and he'll fight" through it.

The matchup against Grispi is slated as the co-main event of UFC 125 in Las Vegas, which is headlined by Frankie Edgar defending his lightweight belt against Gray Maynard.

The featherweight title fight was originally offered to Canadian Mark Hominick, but the Thamesford, Ont., native had to decline as he was recovering from a hand injury suffered prior to his last win over Leonard Garcia at WEC 51 in September. His arm was put in a cast at the beginning of October.

Hominick, who told sporstnet.ca he just had the cast removed and won't be ready to resume full training until next week, is currently slated to take on Team Tompkins training partner George Roop at a UFC Fight for the Troops event on Jan. 22.

Grispi was scheduled to face Erik Koch at WEC 52 earlier this month before it was announced that the UFC would be absorbing its sister organization. The UFC then named Grispi the No. 1 contender to Aldo's title and pulled him from the bout in favour of the UFC championship fight.